An aircraft has various electrically powered devices. For example, such devices are driven by electric motors mounted in the aircraft. An example of such devices is an electrically powered hydraulic pump for supplying hydraulic oil to a hydraulically operated actuator which drives a movable wing, as disclosed in JP 2007-46790 A.
The movable wings are primary control surfaces which are constituted as rudder surfaces such as auxiliary wings (ailerons), rudders and elevators, or secondary control surfaces which are constituted as flaps, spoilers, and the like. Another example of the devices includes an electric actuator which drives the movable wings or legs such as landing gear (a mechanism supporting the body of the aircraft on the ground) or alike.
For example, the electric actuator which serves as an actuator for driving the movable wings has an electric motor and a ball mechanism. A rod of the screw mechanism is displaced by a drive force from the electric motor. The movable wings are displaced in response to the displacement of the rod.
In the case of the electric actuator, external forces such as air pressure act on the electric motor via a steering surface, the screw mechanism and alike during flight of the aircraft. In this case, the electric motor of the electric actuator functions as a power generator since the electric motor operates under the abovementioned external forces to generate regenerative power. JP 2007-46790 A does not consider how to handle such regenerative power. In short, JP 2007-46790 A does not consider effective usage of the regenerative power generated by the electric actuator.
Therefore, if it is attempted to use regenerative power generated by an electric actuator, power is sent from the electric actuator to a distributor situated in the aircraft. However, there may be an excessively large current if shorting or alike causes faults in the electric actuator. If regenerative power is sent to a distributor as described above, there is a risk of an abnormal current flowing in the distributor situated in the aircraft. There is also a risk of an abnormal current (excessively large current) flowing to the distributor resultant from a surge current caused by a lightning strike on the aircraft or alike.